The investigation found many of the horses to be subjected to a cruel practice known as soring -- the intentional infliction of pain to feet and legs to produce an exaggerated gait known as the "Big Lick."

The video shows Jackie McConnell, one of the sport's leading trainers, and his stable hands beating horses with wooden sticks and using electric cattle prods on them to make them lift their feet in the pronounced gait judges like to see. McConnell's staff also apply caustic chemicals to the ankles of the horses and them wrap them with plastic wrap so the chemicals eat into the skin.

"That creates intense pain and then the ankles are wrapped with large metal chains so the horses flinch, or raise their feet even higher," said the Humane Society's Keith Dane.

Soring has been illegal for more than 40 years under the federal Horse Protection Act. As a result of the HSUS investigation, McConnell and his associates have been charged with felony conspiracy to violate the HPA, as well as numerous violations of the Tennessee Cruelty to Animals Statute. McConnell is expected to plead guilty to one count.

Birds were severely overcrowded in cages more cramped than the national average; each hen received only 54–58 square inches of space on which to spend her life.

Injured and dead hens, including mummified bird carcasses, were found inside cages with living hens laying eggs for human consumption.

Hens were left without water for days when a water source malfunctioned, causing many to die.

Hens' legs, wings, and heads were found trapped in cage wires and automated feeding machinery.

A thick layer of dead flies on the barn floors caused a crunching sound when walking on it.

"These allegations by the Humane Society are a gross distortion of Kreider Farms, our employees and the way we care for birds," Ron Kreider, the president of Kreider Farms, told the New York Times' Nicholas Kristof.